1. Field of the Invention
The present invention relates to a support structure for fixedly supporting a drive source such as an electric motor on a fixing member such as a casing through a support member such as a housing, and the invention is effectively applicable to the blower of an air-conditioning system for a vehicle.
2. Description of the Related Art
An electric motor used for the blower of an air-conditioning system for a vehicle (hereinafter referred to as the blower motor), as disclosed in Japanese Examined Utility Model Publication No. 2578063, for example, is fixedly supported on a blower casing (scroll casing) through a flange.
With the recent trend toward lower noise within the vehicular compartments, the noise from the blower motor has become conspicuous. This noise is generated mainly as the vibration of the blower motor is transmitted to the blower casing through a flange and the blower casing radiates the vibration as a sound. With the intention of reducing the vibration and noise, it has been proposed to replace the flange of metal, which is conventionally used, with a flange of resin and mount the blower motor on the flange through an elastic member such as rubber, but they are not sufficient.
Japanese Unexamined Utility Model Publication (Kokai) No. 4-111261, on the other hand, discloses a flange having a rib-like deflector, although the deflector is intended to prevent water from intruding into the motor and is not intended to suppress the vibration.
In view of this situation, the object of the present invention is to provide a support structure for suppressing the generation of noise caused by the vibration of a drive source such as an electric motor.
In order to achieve the aforementioned object, according to one aspect of the present invention, there is provided a support structure for a drive source, comprising a drive source (72) for generating the drive power and a support member (73) for supporting the drive source (72) and fixing the drive source (72) on a fixing member (74), wherein the stiffness of the drive source (72) side portion of the support member (73) is smaller than the stiffness of the fixing member (74) side portion of the support member (73).
As a result, the portion of the support member (73) having a smaller stiffness (which portion is hereinafter referred to as the low-stiffness portion in this embodiment) is more easily vibrated than the fixing member (74) side portion of the support member (73) (which portion is hereinafter referred to as the high-stiffness portion in this embodiment). Thus, the vibration rate of the low-stiffness portion is higher than that of the high-stiffness portion (73e), and the low-stiffness portion vibrates considerably.
Therefore, in the support structure according to this embodiment of the invention, the vibration of the drive source (72) is absorbed into the support member (73) so that the transmission of the vibration of the drive source (72) to the fixing member (74) can be suppressed. As a result, the area of the sound source is reduced as a whole, and the generation of the noise caused by the vibration of the drive source (72) can be suppressed.
According to another aspect of the invention, there is provided a support structure for a drive source, comprising a drive source (72) for generating the drive power and a support member (73) for supporting the drive source (72) and fixing the drive source (72) on a fixing member (74), wherein the elastic modulus of the drive source (72) side portion of the support member (73) is smaller than the elastic modulus of the fixing member (74) side portion of the support member (73).
As a result, the portion of the support member (73) having a smaller elastic modulus (which portion is hereinafter referred to as the low-stiffness portion in this embodiment) is more easily vibrated than the fixing member (74) side portion of the support member (73) (which portion is hereinafter referred to as the high-stiffness portion in this embodiment). Thus, the vibration rate of the low-stiffness portion is higher than that of the high-stiffness portion (73e), and the low-stiffness portion vibrates considerably.
Therefore, in the support structure according to this embodiment of the invention, the vibration of the drive source (72) is absorbed into the support member (73) so that the transmission of the vibration of the drive source (72) to the fixing member (74) can be suppressed. As a result, the area of the sound source is reduced as a whole, and the generation of the noise caused by the vibration of the drive source (72) can be suppressed.
According to still another aspect of the invention, there is provided a support structure for a drive source, comprising a drive source (72) for generating the drive power and a tabular support member (73) for supporting the drive source (72) and fixing the drive source (72) on the fixing member (74), wherein the thickness of the drive source (72) side portion of the support member (73) is smaller than the thickness of the fixing member (74) side portion of the support member (73).
As a result, the portion of the support member (73) having a smaller thickness (which portion is hereinafter referred to as the low-stiffness portion in this embodiment) is more easily vibrated than the fixing member (74) side portion of the support member (73) (which portion is hereinafter referred to as the high-stiffness portion in this embodiment). Thus, the vibration rate of the low-stiffness portion is higher than that of the high-stiffness portion (73e), and the low-stiffness portion vibrates considerably.
Therefore, in the support structure according to this embodiment of the invention, the vibration of the drive source (72) is absorbed into the support member (73) so that the transmission of the vibration of the drive source (72) to the fixing member (74) can be suppressed. As a result, the area of the sound source is reduced as a whole, and the generation of the noise caused by the vibration of the drive source (72) can be suppressed.
According to yet another aspect of the invention, there is provided a support structure for a drive source, comprising a drive source (72) for generating the drive power and a tabular support member (73) for supporting the drive source (72) and fixing the drive source (72) on a fixing member (74), wherein the drive source (72) side portion of the support member (73) includes a bellows portion (h) which comprises a portion which is partly bent and meanders.
As a result, the bellows portion (h) is more easily vibrated than the fixing member (74) side portion of the support member (73) (which portion is hereinafter referred to as the high-stiffness portion in this embodiment). Thus, the vibration rate of the bellows portion (h) is higher than that of the high-stiffness portion (73e), and the bellows portion (h) vibrates considerably.
Therefore, in the support structure according to this embodiment of the invention, the vibration of the drive source (72) is absorbed into the support member (73) so that the transmission of the vibration of the drive source (72) to the fixing member (74) can be suppressed. As a result, the area of the sound source is reduced as a whole, and the generation of the noise caused by the vibration of the drive source (72) can be suppressed.
Incidentally, the reference numerals in parentheses attached to the respective means represent correspondence to the specific means included in the embodiments described later.